Alexander Fleming was a Scottish biologist and pharmacologist who accidentally discovered penicillin in 1928. While searching for antibacterial agents after World War I, Fleming noticed that a fungus in one of his staphylococci cultures had destroyed the surrounding bacteria. He identified the fungus as Penicillium and the substance it produced as penicillin. Although Fleming struggled to develop penicillin further, his discovery later helped scientists Howard Florey and Ernst Chain purify and mass produce penicillin during World War II, saving countless lives. Fleming received widespread recognition for his discovery, including the 1945 Nobel Prize in Physiology or Medicine.

2. Alexander Fleming
Alexander Fleming was a Scottish
biologist and pharmacologist.
He was an inventor of penicillin
in 1928.
Fleming came up with penicillin when he
was trying to find a way to kill bacteria .

3. Early life
Fleming was born on 6 August 1881 at
Loch field, a farm near Darvel, in
Ayrshire, Scotland .
In 1903, the younger Alexander enrolled at
St Mary's Hospital Medical School in
Paddington. He qualified MBBS from the
school with distinction in 1906.

4. Fleming joined the research department at
St Mary's, where he became assistant
bacteriologist to Sir Almroth
Wright , a pioneer in vaccine therapy and
immunology.
He gained a BSc with Gold Medal in
1908, and became a lecturer at St Mary's
until 1914 .

5. Fleming served throughout World War
I as a captain in the Royal Army Medical
Corps.
In 1918 he returned to St Mary's Hospital,
where he was elected Professor of
Bacteriology of the University of
London in 1928.

6. Work before penicillin
Following World War I, Fleming actively
searched for anti-bacterial agents ,
having witnessed the death of many soldiers
from sepsis resulting from infected wounds.
Antiseptics killed the patients' immunological
defences more effectively than they killed the
invading bacteria.

7. Accidental discovery
By 1927, Fleming was investigating the
properties of staphylococci . He was
already well-known from his earlier work,
and had developed a reputation as a
brilliant researcher, but his laboratory was
often untidy.

8. On 3 September 1928 , Fleming
returned to his laboratory having spent
August on holiday with his family .
On returning, Fleming noticed that one
culture was contaminated with
a fungus , and that the colonies of
staphylococci that had immediately
surrounded it had been destroyed, whereas
other colonies farther away were normal.

9. Fleming grew the mould in a pure culture
and found that it produced a substance
that killed a number of disease-causing
bacteria. He identified the mould as being
from the Penicillium genus , and,
after some months of calling it "mould
juice" named the substance it released
penicillin on 7 March 1929.

10. After further experiments, Fleming was
convinced that penicillin could not last
long enough in the human body to kill
pathogenic bacteria, and stopped studying
it after 1931, but restarted some clinical
trials in 1934 and continued to try to get
someone to purify it until 1940.

11. Twelve Years Later
 In 1940, the second year of World War II, two
scientists at Oxford University were
researching promising projects in bacteriology
that could possibly be enhanced or continued
with chemistry. Australian Howard
Florey and German refugee Ernst
Chain began working with penicillin.

12.  Needing the new drug immediately for
the war front, mass production started
quickly. The availability of penicillin
during World War II saved many lives
that otherwise would have been lost due to
bacterial infections in even minor wounds.
Penicillin also treated diphtheria,
gangrene, pneumonia, syphilis
and tuberculosis .

13. Mass Production
On March 14, 1942, the first patient was
treated with U.S.-made penicillin produced
by Merck & Co. Half of the total supply
was used on that one patient.
By June 1942, there was just enough U.S.
penicillin available to treat ten patients.
In July 1943, the War Production Board
drew up a plan for the mass distribution of
penicillin stocks to Allied troops fighting in
Europe.

14. Recognition

After penicillin was completed Alexander
won 25 honorary degrees , metals,
18 prizes and a membership in
87 scientific academies and
societies. He also received the Nobel
Prize in 1945.
 The Royal Polytechnic Institution (now
the University of Westminster) has named
one of its student halls of residence
Alexander Fleming House.

15. Conclusion
This accidental discovery made Alexander
famous and a great scientist. After he
discovered penicillin he tried to discover
many other medicines. Alexander is still
known to this day, he never thought in his
wildest dreams that he would have saved
this many lives.

16. Thank You